Combustion control apparatus using a liquid spray

ABSTRACT

Combustion control apparatus for use with a burner of the type having a centrally located liquid fuel atomizer or a gas ring or center fuel gas arrangement mounted to produce a cone of flame in a combustion chamber. The control apparatus includes a ring of nozzles disposed around the burner and adapted to direct a jet or spray of water or other fluid, such as a slurry or air borne solids onto the flame and an additional duct adapted to direct a stream of air or other fluid onto the flame. The fluid is adapted to eliminate excessively hot combustion zones by cooling the flame at such zones and eliminating temperature peaks for thereby increasing the period of combustion in the chamber so as to reduce or eliminate the formation of undesirable oxidation products which are formed at high temperature.

United States atent Dunn [ COMBUSTION CONTROL APPARATUS Inventor:Assignee:

Filed:

Appl. N0.:

US. Cl. 431/4, 431/190 Int. Cl. F231 7/00 Field of Search 431/4, 190,181,

References Cited UNITED STATES PATENTS 3,101,592 8/1963 Robertson et al.60/3905 X 2,867,267 1/1959 Nerad et a1. 431/190 FOREIGN PATENTS ORAPPLICATIONS 125,327 5/1958 U.S.S.R 431/187 430,738 2/1935 Great Britain431/4 Primary Examiner-William ODea Assistant Examiner-William C.Anderson AttorneyNathaniel L. Leek [57] ABSTRACT Combustion controlapparatus for use with a burner of the type having a centrally locatedliquid fuel atomizer or a gas ring or center fuel gas arrangementmounted to produce a cone of flame in a combustion chamber. The controlapparatus includes a ring of nozzles disposed around the burner andadapted to direct a jet or spray of water or other fluid, such as aslurry or air borne solids onto the flame and an additional duct adaptedto direct a stream of air or other fluid onto the flame. The fluid isadapted to eliminate excessively hot combustion zones by cooling theflame at such zones and eliminating temperature peaks for therebyincreasing the period of combustion in the chamber so as to reduce oreliminate the formation of undesirable oxidation products which areformed at high temperature.

9 Claims, 2 Drawing Figures Patented July 24, 1973 3,748,080

I /5 l/l I 1 INVENTOR.

John Dunn ATTORNEY COMBUSTION coNTRoI. APPARATUS USING A LIQUID SPRAYThis invention relates to combustion control apparatus and has for anobject to control the period of combustion in a manner to eliminate orreduce the formation of undesirable oxides.

A more specific object is to eliminate or reduce the formation of oxideas of nitrogen.

Another object is to provide means for introducing a cooling fluid or achemical reactant into a flame at zones selected to produce the aboveresult.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

In accordance with the present invention a ring of liquid nozzles isdisposed around the throat opening of a fuel burner in such a mannerthat water or other liquid can be directed upon the cone of flame atvarious selected locations. The liquid is intended to prevent local hotzones in the flame which tend to produce undesired combustion productssuch as oxides of nitrogen or other elements which are known in the artto be undesirable from the standpoint of flue gas contaminants and as anindication of incomplete combustion.

The nature of the invention will be better understood .from thefollowing description, taken in connection I a burner throat opening 11formedby a ring of throat tile 12. A front wall 13 is spaced from thefurnace wall 10 to form a plenum chamber 14 therebetween. The

burner elements includean air register 15 having a front plate 16secured to the front wall 13 and registering axially with a burner tube17 having a rear flange 18 bolted to a plate 19 secured to the wall 10.Gas ring 20 of usualtype for supplying gaseous fuel is secured betweenthe flange l8 and the plate 19 adjacent throat opening'll. A fuel barrel21- of the type carrying gaseous liquid or pulverized fuel extendsaxially through the air register 15 and burner tube 17 with an atomizingtip 22 disposed axially at the burner throat 11. v

The elements thus far described are of standard construction and only somuch thereof has been shown as is necessary for an understanding of theinvention.

For the purpose above-described a liquid ring 30 is disposed around theburner throat opening 11 and spaced radially outwardly from the gas ring20. The liquid ring 30 is secured to the plate 19 by suitable meansshown as bolts 31 and is supplied with water or other fluid through apipe 32 having a control valve 33. A plurality of pipes 34 extend fromthe liquid tube 30 through axially inclined openings 36 in the wall 10and terminate in nozzles 37 which are disposed around the throat opening11 at an angle such that a spray of water or other fluid is directedonto the flame 38 from the burner tip 22. The angle of the spray fromthe nozzles 37 may be controlled by deflectors 39 which are pivoted tothe nozzles and are controlled by rods 40 extending through the wall 10and connected to any suitable manual or automatic control means.Deflectors 39 may be adjusted to control the radial angle of the liquidspray from thenozzles 37 so as to direct the spray onto any selectedportion of the flame 38. This spray of water is adapted to control theflame temperature in a manner to reduce the formation of undesiredcombustion components.

For an additional control of the flame temperature and the combustionconditions a series of air ducts are shown extending through the wall 10around the throat opening 11 for admitting air from duct 47 controlledby a valve 48, a manifold 46 having an inlet duct which may be connectedto admit air or other fluid from any suitable source or may be open tothe plenum chamber 14 for admitting air from such chamber into the ducts45-. Deflector plates 50 may be pivoted manually on the ducts 45 andcontrolled by rods 51 by any suitable means for controlling the angle atwhich the air or other fluid from the ducts 45 is discharged onto theflame 38.

In operation the deflector plates 39 and 50 are adjusted in accordancewith the combustion conditions to cause the liquid or gas streams fromthe nozzles 37 or ducts 45 to impinge on any excessively hot portions ofthe flame 38 so as to reduce the temperature and retard combustion atsuch portions and thus increase the period of combustion in thecombustion chamber to an extent suited to cause complete combustion andto avoid the formation of undesirable oxidation products.

The jet from the nozzles 37 may comprise water or a chemical compositionor slurry which may be particu' larly adapted to control the combustionproducts. Likewise the jets from the ducts 45 may comprise airor areagent or an inert gas as may be required for the above purpose.Various combustion control materials are'well known in the art and maybe used in the present apparatus.

What is claimed is:

1. In combination with a furnace having a'wall provided with an openingforming a burner throat, a

burner tube connected to supply air for combustion to said throat and afuel barrel disposed axially of said burner tube and having a tipadaptedito produce a cone of flame, a series of nozzles extendingthrough said wall around said throat opening and adapted to project aliquid spray onto said cone of flame, an annular header disposed tosupply liquid to said nozzles, and means to adjust the radial angle ofsaid spray for controlling the zone of impingement of said liquid sprayon said cone of flame.

2. Apparatus as set forth in claim 1 in which said means for adjustingthe radial angle of said liquid spray comprises deflector platesdisposed adjacent eachnozzle to direct the spray onto selected portionsof said cone of flame.

3. Apparatus as set forth in claim 2 including means for adjusting theangular positions of said deflector plates.

4. Apparatus as set forth in claim 1 including a set of gas passagesextending through said wall around said throat opening adapted to directa gas onto said cone of flame.

5. Apparatus as set forth in claim 4 including means supplying a gas tosaid passages and means to control the quantity of such gas.

from a plurality of sources disposed peripherally around said throatopening and controlling the angular direction of said spray to eliminatelocal hot zones and to thus increase the period of combustion so as toeliminate the formation of undesirable oxides in the products ofcombustion.

9. The method set forth in claim 8 in which a gas is projected onto saidcone of flame from a plurality of external sources disposed around saidthroat opening. l

1. In combination with a furnace having a wall provided with an openingforming a burner throat, a burner tube connected to supply air forcombustion to said throat and a fuel barrel disposed axially of saidburner tube and having a tip adapted to produce a cone of flame, aseries of nozzles extending through said wall around said throat openingand adapted to project a liquid spray onto said cone of flame, anannular header disposed to supply liquid to said nozzles, and means toadjust the radial angle of said spray for controlling the zone ofimpingement of said liquid spray on said cone of flame.
 2. Apparatus asset forth in claim 1 in which said means for adjusting the radial angleof said liquid spray comprises deflector plates disposed adjacent eachnozzle to direct the spray onto selected portions of said cone of flame.3. Apparatus as set forth in claim 2 including means for adjusting theangular positions of said deflector plates.
 4. Apparatus as set forth inclaim 1 including a set of gas passages extending through said wallaround said throat opening adapted to direct a gas onto said cone offlame.
 5. Apparatus as set forth in claim 4 including means supplying agas to said passages and means to control the quantity of such gas. 6.Apparatus as set forth in claim 5 in which a manifold is connected tosaid passages and means is provided to supply a controlled quantity of agas to said manifold.
 7. ApparAtus as set forth in claim 4 in which saidgas passages are peripherally displaced around said throat opening. 8.The method of controlling the flame in a fuel burner having a burneradapted to produce a cone of flame in a throat opening in a furnace wallwhich comprises directing a liquid spray onto said cone of flame from aplurality of sources disposed peripherally around said throat openingand controlling the angular direction of said spray to eliminate localhot zones and to thus increase the period of combustion so as toeliminate the formation of undesirable oxides in the products ofcombustion.
 9. The method set forth in claim 8 in which a gas isprojected onto said cone of flame from a plurality of external sourcesdisposed around said throat opening.